A gear transmission is known in which a plurality of gears is housed in a case, and a carrier is supported by the case via a bearing. A gear transmission in which a cylindrical roller bearing is disposed between a case and a carrier is disclosed in Japanese Patent Application Publication No. 2010-159774 (called Patent Document 1 below). In the cylindrical roller bearing of Patent Document 1, cylindrical rollers (rolling elements) are inclined with respect to an axis of the carrier. Since the rollers are inclined with respect to the axis of the carrier, force to move the rollers outward is applied to the rollers along with a rotation of the carrier.